I’ve been puzzling over something for a goodly time now, and have–defeated–thrown in the towel. At your mercy, I must ask for your indulgence, and assistance. In return, your questions too shall be addressed and, I hope, answered to your satisfaction.
What is my conundrum? Simply this: since the debut of my blog, the stats gathered by the WordPress servers consistently indicate large number of views for my post “Counting Ribs”, more than any other. Many, apparently, result from searches such as ‘how to count ribs,’ ‘counting ribs on chest x-ray,’ and the like. Of course, if you read that post you quickly realize that it isn’t really about the ribs, much less an instruction manual for how to count them. Seeing the stats month after month, and imagining the disgust or disappointment of those who find my offering deficient, I confess I feel no small twinge of guilt. Read on, and I will remedy the earlier deficiency. First, though, a few words about the ribs and their various afflictions.
Well, ok, first I need you to read the standard disclaimer: this site and blog post are not intended to provide medical advice, nor do they in any way represent the organization I work for. If you are having health issues you should seek the care of a medical professional–in person.
I can’t help but wonder why so many people seek this information. Do they have a rib fracture, or other problem? Do they know someone who does? Do they think the precise locus of this issue carries a unique, particular import? Has their doctor diagnosed a rib disorder, but not shown them its ghostly tracing on their x-ray? Are they having pain, or have they found a lump, and wonder which rib might be the offender?
In most cases, the exact site of a rib fracture matters relatively little. It makes no difference whether a fracture finds itself in the sixth rib, the eighth, or the fifth, or on the left side versus the right. An important exception concerns fractures of the first 3 ribs: these tight curved flutes, huddled close against the apex of the lung, are not easily disrupted. A break in one, or all, of them implies trauma to the chest sufficient to cause other, more serious damage–to the large arteries or veins in the chest, to the pleura (the lining of the chest cavity that surrounds the lung), or even to the heart. This generally occurs in high-speed car crashes, or falls from great heights, and is a well known sign of important chest injury. Every first-year radiology resident is taught to look for it, and to raise the red flag whenever it is found.
Another exception relates to other structures in the neighborhood that could be injured by the initial insult, or by the broken edges of a fractured rib. Fracture of the lower ribs, for example, can be associated with, or lead to, damage to the liver, spleen, or other organs. These too are often the result of major trauma, and aren’t as important in their own right as for what they signify. The number of ribs that are fractured can be important, as a string of five or more can cause the chest wall to break ranks when the patient tries to breathe, moving out when it should move in and vice versa–or not moving at all. This condition, known as flail chest, can cause major compromise of gas exchange. There’s also a high chance of pneumothorax, or punctured lung, when more than a single rib is broken.
Other things that can befall the ribs include a panoply of tumors, benign or malignant, infection, cysts and other non-tumorous growths, metabolic problems, and assorted other rarities. For most of these, their specific location isn’t important.
All that aside, the thing about counting ribs is that it’s tricky. First of all, not everyone has the same number of the things: twelve on each side is standard, but some of us have eleven, while others have 13….and there can be asymmetry between left and right sides. Extra ribs, if present, may be at the top or bottom end. For this reason, it’s most accurate–though also, potentially, most confusing–to start counting from the top, rather than the bottom if you really need to know exactly which rib is acting up. That’s harder because, as I noted earlier, the first few ribs are small and jammed together tightly in the upper chest. As a result, they overlap on chest x-rays, creating all manner of perplexing curves and shadows. The good news is that extra ribs at the upper end of the spine, so called ‘cervical ribs’, are easy to recognize and discount. That’s because they are generally very small and don’t look at all like the neighboring normal ribs.
Here are a few images of the ribs in various projections (degrees of obliquity), without and with annotations to show the count. Note that it’s best to start where each rib joins the spine and follow it outward (laterally). The initial portion of each rib is more or less straight, but they curve downward as you follow them around the side to the front of the chest–hence the apparent jumble and overlap of numbers in some areas. You may need to try it a few times, but just remember to start near the spine and work your way out from there. Give it a go….and leave me a comment about why you’re interested in counting ribs!
frontal view of the ribs, without numbering
frontal view with numbering
oblique view #1
oblique view #1 with numbering
oblique view #2
oblique view #2 with numbering
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